thanks for the answer.
if I instead of the 8255 chooses the Onkyo TX-SR309 http://www.eu.onkyo.com/en/products/tx-sr309-35373.html
which would you then recommend?
Or which alternative would you recommend for that size room?
Which of these systems would you recommend for a 20m2 room?
my budget are 350 - 530$.
Onkyo TX-8255 http://www.eu.onkyo.com/en/products/tx-8255-34863.html
+
Yamaha NS-125F http://usa.yamaha.com/products/audio-visual/speaker-systems/home-speaker-systems/ns-125f_piano__u/?mode=model
or
Onkyo...